The U.S. Supreme Court building in Washington, D.C. (Chip Somodevilla/Getty Images)

SAN JOSE (CBS SF) – Several Bay Area lawyers and law professors said Monday’s U.S. Supreme Court decision on police use of electronic tracking devices on cars may bring citizens more protection from technological surveillance and will affect a number of local cases.

“I’m sure it will affect scores of cases in the San Francisco Bay Area and hundreds nationwide,” said Golden Gate University law professor Peter Keane.

The high court unanimously overturned the cocaine conspiracy conviction and life sentence of a Washington, D.C., nightclub owner whose trial featured evidence from a global positioning system tracking device secretly planted on the car by the FBI.

The device was on Antoine Jones’s car for 28 days.

KCBS’ Holly Quan Reports:

The court said the use of the tracker without a court-approved warrant amounted to a search in violation of the Constitution’s Fourth Amendment, which forbids unreasonable searches and seizures.

Keane and Santa Clara University law professor Kyle Graham said the ruling can now be used as a basis for challenges in criminal and civil cases in which the tracking devices were used without a warrant.

“If I were a defense attorney, I’d press it,” Graham said.

“For the past 20 years, most police departments have been going ahead and attaching a lot of global positioning systems on vehicles,” said Keane, who said authorities had relied on previous decisions that seemed to allow warrantless use of the devices.

Among other cases, the ruling is expected to influence a South Bay college student’s lawsuit against the FBI for placing a secret GPS device on his car in 2010 and Yusuf Bey IV’s appeal of his conviction in the 2007 murder of Oakland journalist Chauncey Bailey.

But the two professors also said that while the decision shows the high court’s justices are concerned about technological intrusion, it left open many questions about how the ruling will be applied.

“It’s not clear that it will have a sweeping effect,” Graham said.

“It does show the use of technological devices such as a GPS is not going to evade scrutiny, but it leaves open what degree of scrutiny they will receive,” Graham said.

Graham and Keane said the reason for the lack of clarity is that while a government action defined as a Fourth Amendment search normally requires a judicial warrant authorizing the search, the court didn’t discuss when and how exceptions might apply.

Possible exceptions include emergency situations and situations in which prosecutors are able to prove later to a judge that the search was in fact reasonable even though no warrant was obtained.

The court declined to address the U.S. Justice Department’s claim that the warrantless search of Jones’s car was reasonable. Thus, the panel set no guidelines for applying that exception.

“It opened up a whole slew of questions” to be resolved in later cases, Keane said.

The San Francisco-based Electronic Frontier Foundation, a cyberspace civil liberties group, said it is optimistic the decision will increase citizens’ protection from new surveillance technology.

“This is an important ruling for all Americans,” said EFF attorney Marcia Hofmann.

“The Supreme Court has unanimously confirmed that the Constitution prevents unbridled police use of new technologies to monitor our movements,” she said.

Lawyers for Yasir Afifi, the student who sued the FBI, praised the decision and predicted it will help their case.

“This is good news for our client’s case. We’re really excited,” said Zahra Billoo, a lawyer with the San Francisco Bay Area Office of the Council on American-Islamic Relations.

Afifi, 21, of San Jose, is a U.S. citizen whose father is Egyptian. He is majoring in business marketing at Mission College in Santa Clara.

His lawsuit, filed in federal court in Washington, D.C., last year, says that on Oct. 3, 2010, he discovered a global positioning system tracking device on the underside of his car after he stopped at a mechanic’s shop for an oil change.

Fearing that the black rectangular object might be a bomb, he posted a picture of it on the Internet and learned it was a tracking device.

Two days later, FBI agents appeared at his doorstop to interrogate him and demand that he return the device, according to the lawsuit.

The suit, which claims the FBI violated the Fourth Amendment as well as his First Amendment free-speech right, was put on hold until the Supreme Court ruled in the Jones case.

“It ensures that it’s not just a neighbor who’s mad at me calling the police to say I’m a terrorist,” she said.

Graham noted, however, that FBI officials defending themselves against Afifi’s lawsuit might be able to argue they believed the technology was legal in western states at the time, because the San Francisco-based 9th U.S. Circuit Court of Appeals had allowed it in another case in early 2010.

Another federal appeals court in Washington, D.C., had ruled the opposite way, and Monday’s high court decision resolves the conflict.

In the Bey case, the former Your Black Muslim Bakery leader was convicted of Bailey’s murder in an Alameda County Superior Court trial that included evidence from a warrantless tracking device placed on his car six weeks earlier in connection with an unrelated investigation.

The data didn’t prove Bey’s whereabouts, but showed that the car drove by Bailey’s home the day before and an hour after the murder on Aug. 2, 2007.

Bey’s lawyers argued unsuccessfully in a pretrial hearing that the use of the GPS device was illegal and are expected to raise the issue again in his appeal.

Keane said that because there was a lot of other evidence against Bey, prosecutors might be able to argue that even if the GPS evidence was illegal, it was a so-called harmless error that doesn’t justify overturning the conviction.

Bey, 26, was sentenced to three consecutive life sentences for ordering the murders of Bailey and two other men.

(Copyright 2012 by CBS San Francisco and Bay City News Service. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)